990-05-XX-03-CN | Bently Nevada | 990 Vibration Transmitter (2024)

FAQs

How do you test a vibration transmitter? ›

Use a vibration shaker or exciter to generate controlled vibrations. Apply different frequencies and amplitudes to the sensor and measure the corresponding output signals. This test helps determine the sensor's frequency response and linearity.

They work on the eddy current principle, where the sensor coil impedance changes as the gap between the probe and the rotating equipment changes due to vibration.

Probes are connected to 9 meter system Bentley Nevada proximitor having part number 18745-04,and output connected to Bentley Nevada 3300 panel.

The vibration transmitter's 4-20 mA output is proportional to overall acceleration vibration. The sensor also outputs the dynamic acceleration signal.

In order to test a pressure transducer, you need to connect the transmitter to the multimeter and use the suitable excitation voltage to excite the transmitter. At zero load, measure the transmitter's voltage output. Record the voltage and compare it to the manufacturer's datasheet's no-load voltage specification.

Most internally amplified vibration sensors require a constant current DC power source. Generally, the power supply contains an 18 to 30 volt source with a 2 to 10 mA constant current diode (CCD) (see Figure 1).

This output or sensitivity is linear for the most part within the frequency response window of a sensor. However, it is not always DOT 100 mV/g. The sensitivity varies and can vary up to 5 to 10% both ways (plus and minus). This variation is also called the Accuracy of the Sensor.

Gap voltage is the voltage in the gap between two electrodes. The total energy of the spark is determined by the applied voltage. Depending on the setting of the voltage, the IEG is set by the servo control.

Bently Nevada was privately held until 2002 when it was acquired by General Electric and became part of GE Oil and Gas.

An accelerometer or ceramic piezoelectric sensor is commonly used to measure vibration. Most accelerometers rely on the use of the piezoelectric effect, which occurs when a voltage is generated across certain types of crystals as they are stressed.

What frequency does a vibration probe work at? ›

Industrial vibration sensors are suitable for measuring vibrations at medium strengths. These sensors have a sensitivity of 100 mV/g and their typical frequency band ranges from 1 Hz to 8000 Hz. At the lower end of the scale, the so-called seismic vibration sensors are built to detect very weak vibrations.

Vibration sensors are used for monitoring systems, whereas vibration transmitters are used for control system inputs.

The gravitational acceleration g = 9.8 m/s^2 can be used as a unit just as well as 1 m/s^2, and will be convenient when you want a comparison with objects that are either falling or standing up under earth's gravity. For example if a surface is vibrating at 1 g, objects placed on top will start to lift off.

RMS (Root Mean Square) frequency of a spectrum is a single number that represents the overall level of energy across a frequency range. Basics of RMS (Root Mean Square) frequency in Vibration Analysis: It is challenging part to collect vibration data in vibration management and analysis of data collected.

Disconnect one end of the measuring signal leads, and connect a multimeter or a loop calibrator in series with the transmitter circuit. Note the mA reading, which is expected to be between 4mA and 20mA. If the reading is not between the expected ranges then calibration is required.

An accelerometer or ceramic piezoelectric sensor is commonly used to measure vibration. Most accelerometers rely on the use of the piezoelectric effect, which occurs when a voltage is generated across certain types of crystals as they are stressed.